If you ever played GTPSP then you'll realize that you can play your own music through your game!

I may be new in this forum, but I found this very useful...

IMPORTANT:
COMPLETE CHALLENGE GROUP A FIRST TO UNLOCK USER BGM FEATURE!!

Now follow my instructions for your GTPSP User BGM!
(You can do this in PC or in Android)
1: Open your Gran Turismo
2: When you reached the main menu, go to settings/options
3: In the settings/options screen, go to the 3rd tab (Audio)
4: In that tab, find User BGM Folder and choose either MUSIC Folder or MUSIC/GTPSP Folder
5 (Optional): Put your BGM volumes to 100
6: Close PPSSPP and open any file managers
7: In your Internal Memory, create a folder named MUSIC. If you already have a Music folder, just rename it to MUSIC (all caps)
8 (Optional): If you selected MUSIC Folder, you're done. If you selected MUSIC/GTPSP Folder, create another folder inside the MUSIC folder and name it GTPSP
9: Find a copy of your desired music
(MAKE SURE YOUR MUSIC IS ON MP3 FORMAT AND HAS ATLEAST 128 BIT. YOU CAN DOWNLOAD AND INSTALL MP3 VIDEO CONVERTER TO CONVERT ANY AUDIO/VIDEO TO MP3. YOU CAN ALSO SELECT YOUR DESIRED BIT)
10: Once you found your music, copy or cut it to MUSIC folder IF YOU SELECTED MUSIC in User BGM Folder. And in GTPSP folder IF YOU SELECT MUSIC/GTPSP in User BGM Folder. Remember, its located inside the MUSIC folder
11: Run Gran Turismo again and head over to the settings/options again
12: Go to the Audio Tab and configure the BGM volumes. If your music plays, congrats!

PS: I dunno if there is a limit for your musics, just put everything you wanted to listen to while racing!